Location Of Occlusion Research Articles

Risk of Symptomatic Intracranial Hemorrhage After Mechanical Thrombectomy in Randomized Clinical Trials: A Systematic Review and Meta-Analysis

Background: Symptomatic intracranial hemorrhage (sICH) is the most dreaded complication after reperfusion therapy for acute ischemic stroke. We performed a meta-analysis of randomized controlled trials to estimate and compare risks of sICH after mechanical thrombectomy (MT) depending on the location of the large vessel occlusion, concomitant use of intravenous thrombolysis, timing of treatment, and core size. Methods: Randomized controlled trials were included, following a comprehensive search of different databases from inception to 1 March 2024. Random-effect models in a meta-analysis were employed to obtain the pooled risk ratios (RRs) and their corresponding 95% confidence intervals (95% CI) for sICH with MT, and were then compared to other reperfusion treatment regimens, including best medical treatment and intravenous thrombolysis (IVT). Results: MT in the anterior circulation was associated with a significantly higher risk of sICH as compared with no-MT (RR: 1.46; 95%CI: 1.03–2.07; p = 0.037). The risk of sICH was comparable between the MT and MT+IVT groups (RR: 0.77; 95%CI: 0.57–1.03; p = 0.079). There was no difference in sICH risk with MT as compared with no-MT within 6 h of last known well (RR: 1.14; 95%CI: 0.78–1.66; p = 0.485) and beyond that time (RR: 1.29; 95%CI: 0.80–2.08; p = 0.252); the risk of sICH was also comparable between MT conducted within 6 h of last known well and MT conducted beyond that time (p = 0.512). The sICH risk for MT in the posterior circulation (RR: 7.48; 95%CI: 2.27–24.61) was significantly higher than for MT in the anterior circulation (RR: 1.18; 95%CI: 0.90–1.56) (p = 0.003). MT was also associated with a significantly higher sICH risk than no-MT among patients with large core strokes (RR: 1.71; 95%CI: 1.09–2.66, p = 0.018). Conclusions: When evaluating cumulative evidence from randomized controlled trials, the risk of sICH is increased after MT compared with patients not treated with MT. Yet, the difference is largely driven by the greater risk of sICH in patients treated with MT for posterior circulation occlusions and, to a lesser degree, large core strokes. Concomitant use of intravenous thrombolysis and the use of MT in the extended therapeutic window do not raise the risk of sICH.

Hemodynamic Insights Into the Asymmetrical Medullary Vein Sign on T2* Imaging in Hyperacute M1 Occlusion.

Background In treating acute ischemic stroke (AIS), asymmetrical vein signs (AVS) on blood-oxygen-level-dependent imaging reflect increased deoxyhemoglobin levels due to increased oxygen extraction fraction. Meanwhile, although veins connecting pial and deep venous systems, such as transcerebral veins, are well studied, dynamic observation of these veins remains challenging. This study aimed to elucidate the venous flow of the deep white matter (DWM), focusing on medullary AVS in patients with hyperacute cardioembolic M1 occlusion. Methods This retrospective cross-sectional study involved 50 patients with AIS caused by M1 occlusion who received mechanical thrombectomy at Kameda Medical Center from July 2018 to December 2021. The study investigated medullary AVS and their association with angiographic collateral flow grades and occlusion locations. Welch's t-test was used for continuous variables, while Fisher's exact test was employed for categorical variables. Results A total of 41 patients were eligible for analysis. No significant association was found between medullary AVS and angiographic collateral flow grade (p=1.000); however, a significant association was observed between proximal M1 occlusion and medullary AVS (p=0.006), supporting the hypothesis that medullary AVS is significantly influenced by ischemic conditions in the territory of lenticulostriate arteries. Conclusion Three possible mechanisms for medullary AVS were considered: local ischemia in the DWM, ventriculopetal ischemic venous flow from the pial veins, and ventriculofugal ischemic venous flow from the basal ganglia. The results of the present study and the fact that the DWM is exclusively perfused by the cortical arteries favor the ventriculofugal flow hypothesis as the mechanism of medullary AVS. Although direct observation of the veins in the DWM by cerebral angiography is challenging, it can be deduced indirectly.

Stent-retriever alone vs. combined technique with balloon guide catheter in large vessel occlusion stroke: A single center experience

Background: Today, balloon guide catheters are widely used in thrombectomies. This study aimed to compare the demographic, angiographic, and clinical outcome parameters of thrombectomy for anterior circulation large vessel occlusion strokes (LVOS) using a first-line stent retriever (SR) alone with those of a thrombectomy using a technique combining a balloon guide catheter (BGC) with a distal access catheter (DAC) and an SR. Methods: We retrospectively analyzed the data of patients who had experienced anterior circulation LVOS and underwent mechanical thrombectomy with a BGC at our stroke center between January 2015 and December 2022. The patients were divided into two groups based on the techniques used in the thrombectomy: a stent retriever alone (BGC+SR) and a combined approach (BGC+DAC+SR). Baseline characteristics, procedure details, angiographic results, and clinical outcomes were assessed. The primary clinical outcome in this study was the rate of functional independence (mRS score ≤2) at 90 days. The primary technical outcome was the rate of first pass effect (FPE), defined as achieving near complete/complete revascularization (modified thrombolysis in cerebral infarction [mTICI] 2c-3) after a single treatment pass. Secondary outcomes included mortality at 90 days, procedural complications, embolic complications, and symptomatic intracranial hemorrhage. Results: Out of 234 patients, 137 (58.6%) were in the BGC +SR group, while 97 (41.4%) were in the BGC+SR+DAC group. Patients treated with BGC and SR alone were younger (median age 58 vs. 61 years, p=0.005) and had a higher prevalence of middle cerebral artery occlusions (M1 segment: 64.9% vs. 37.5%; M2 segment: 14.9% vs. 5.2%, p<0.001) compared to those in the combined group. The BCG+SR group had a greater incidence of cardioembolism and embolic stroke of undetermined source (49.3% vs. 41.1%, 26.5% vs. 12.6%, respectively, p=0.007). The median NIHSS of the entire population was 15 (IQR, 11–18), and 108 (46%) patients received intravenous thrombolytics before thrombectomy. The patients treated with the combined technique tended to have higher rates of FPE compared to those in the BGC+SR (47.4% vs. 35.8%, p=0.074) and higher rates of successful (≥mTICI 2b) and excellent (≥mTICI 2c) recanalization overall (93.8% vs. 90.5% p=0.504; 78.4% vs. 71.5%, p=0.306, respectively). The groups had similar rates of good clinical outcome (mRS 0-2) and mortality at 90 days (61.7% vs. 53.3%, p=0.21;14.3% vs. 18.7%, p=0.495, respectively) with comparable rates of complications. Multivariate analyses identified higher baseline Alberta Stroke Program Early CT scores (OR=1.19; 95% CI, 1.09–1.28) and middle cerebral artery M1 occlusion locations (OR=1.90; 95% CI, 1.45–2.42) as independent predictors of first-pass success. Conclusion: In this study, treating acute ischemic strokes with an anterior system large vessel occlusion using a thrombectomy technique employing a BGC with an SR resulted in similar recanalization and FPE rates as using a technique employing a BGC in combination with an SR and a DAC. Both first-line strategy techniques had similar rates of good clinical outcome (mRS score ≤2) and mortality at 90 days.

Cerebral Infarct Growth: Pathophysiology, Pragmatic Assessment, and Clinical Implications.

Cerebral ischemic injury occurs when blood flow drops below a critical level, resulting in an energy failure. The progressive transformation of hypoperfused viable tissue, the ischemic penumbra, into infarction is a mechanism shared by patients with ischemic stroke if timely reperfusion is not achieved. Yet, the pace at which this transformation occurs, known as the infarct growth rate (IGR), exhibits remarkable heterogeneity among patients, brain regions, and over time, reflecting differences in compensatory collateral flow and ischemic tolerance. We review (1) the pathophysiology of infarct growth, (2) the advantages and pitfalls of different approaches of IGR measurement, (3) research gaps for future studies, and (4) the clinical implications of stroke progressor phenotypes. The estimated average IGR in patients with acute large vessel occlusion stroke is 5.4 mL/h although there is wide variability based on ischemic stroke subtype, occlusion location, presence of collaterals, and patient baseline status. The IGR can be calculated using various pragmatic strategies, mostly either quantifying the extension of the infarct at a particular time and dividing this measure by the time that elapsed from symptom onset to imaging assessment or by using collateral blood flow status as a radiological surrogate marker. The IGR defines a spectrum of clinical stroke phenotypes, often dichotomized into fast and slow progressors. An IGR ≥10 mL/h and the perfusion metric hypoperfusion intensity ratio ≥0.5 are commonly used definitions of fast progressors. A nuanced understanding of the IGR and stroke progressor phenotypes could have clinical implications, including informing prognostication, acute decision-making in peripheral-to-comprehensive transfer patients eligible for thrombectomy, and selection for adjuvant neuroprotective agents.

Abstract 161: Variations in Mechanical Thrombectomy Techniques and Impacts Based on Occlusion Location: INSPIRE‐S Global Registry Insights

Introduction/Purpose The primary mechanical thrombectomy (MT) techniques currently utilized are stent retriever (SR) only,aspiration (ASP) only, and combination therapy (CT), with the general aim of achieving first‐passrecanalization (FPR:TICI≥2c). While differences in effectiveness among these techniques are generallymodest, they may be more pronounced in specific patient subgroups, conceivably those categorized byocclusion location. Furthermore, the benefits of technique variations, like the choice between manualaspiration and aspiration pump, are unclear. Materials/Methods INSPIRE‐S is a global, prospective registry of stroke patients treated with Medtronic Neurovasculardevices, with data adjudicated by imaging core lab and safety clinical events committee. The registrygroups patients based on the initial MT technique used. Although some studies have compared theoutcomes of different techniques across various occlusion locations, clear evidence is lacking.Additionally, real‐world data on the impact of aspiration methods (manual vs. pump) is limited. Results Between May 2020 and December 2022, 802 patients from 29 sites in 13 countries were enrolled andfollowed for 90 days: 259 treated with SR, 146 with ASP, and 397 with CT. Most occlusions (76.1%)occurred in the MCA‐M1/M2 regions. Significant differences in occlusion location were observed amongtechniques. Fewer patients with MCA‐M1/M2 occlusions were treated with ASP (ASP: 65.2%, SR: 76.1%,CT: 80.1%; p<0.01), while more patients with ICA occlusions (ASP: 22.7%, vs SR: 13.8%; p=0.03 and vs CT:15.2%; p=0.05) and BA occlusions (ASP: 9.2%, vs CT: 3.9%; p=0.03, but not vs SR: 6.1%; p=0.31) weretreated with ASP. Across the three technique groups, final complete reperfusion, FPR and good clinicaloutcomes (mRS≤2 or mRS≤pre‐stroke mRS) at 90 days were similar (Final SR: 77.5%, ASP: 70.6%, CT:72.0%; FPR SR: 48.6%, ASP: 39.9%, CT: 47.5%; mRS SR: 60.5%, ASP: 52.8%, CT: 56.6%). No significantdifferences were found in all‐cause mortality (SR: 13.1%, ASP: 14.4%, CT: 14.4%; p=0.91) or symptomaticintracranial hemorrhage within 24 hours (SR: 1.5%, ASP: 1.4%, CT: 1.5%; p=1.00). Subgroup analysisrevealed that in ICA occlusions, ASP had the lowest FPR (12.5%) compared to SR (50.0%; p=0.001) and CT(40.7%; p=0.008). ASP also underperformed in ICA (12.5%) compared to BA (76.9%) and MCA‐M1 (46.9%)for FPR (p<0.001). However, ASP showed the highest FPR (numerically) in BA occlusions. The use of anaspiration pump in the ASP group was linked to better 90‐day mRS 0‐2 outcomes compared to manualaspiration (59.8% vs. 36%, p=0.008, adjusted p=0.015), with no significant differences in final completereperfusion (68.1% vs. 69.8%) or FPR (39.7% vs. 37.7%). Similar trends were observed in the CT group formRS 0‐2 (58.7% vs. 48.3%, p=0.06). Conclusions INSPIRE‐S data from a diverse, large‐scale patient population shows that reperfusion, clinical, and safetyoutcomes were similar regardless of the first‐line MT technique used. Notably, while ASP was mostfrequently employed for ICA occlusions, it was associated with the lowest FPR rates. Use of an aspirationpump improved 90‐day mRS outcomes compared to manual aspiration. These findings suggest thatfurther research is warranted to determine the optimal use of different MT techniques depending onocclusion location.

Mechanical Thrombectomy for Treatment of Acute Cerebral Infarction due to Distal Medium Vessel Occlusions: A Retrospective Cohort Study.

Mechanical thrombectomy (MT) is standard of care for acute cerebral infarction (ACI) due to large vessel occlusions. However, its clinical efficacy in patients with ACI due to distal medium vessel occlusions (DMVOs) remains unclear. This study evaluates the efficacy and safety of MT in patients with ACI due to DMVOs. Totally, 306 patients with ACI at a very early stage were assigned into DMVOs-MT, M1-MT, and DMVOs-intravenous thrombolysis (IVT) groups. These groups were compared regarding baseline data, recanalization rate, location of vessel occlusions, number of thrombectomy, first-pass recanalization, mRS scores, NIHSS scores, 90-day mRS scores, incidence of adverse events, and mortality. Risk factors for poor prognosis of patients with DMVOs following MT were analyzed. DMVOs-MT and M1-MT groups showed comparable first-pass recanalization rates, recanalization rates, and NIHSS score reduction ratios, with marked differences in location of vessel occlusions. Versus DMVOs-IVT, DMVOs-MT had increased differences between pre- and post-treatment NIHSS scores and between pre-treatment NIHSS scores and NIHSS scores at discharge and elevated NIHSS reduction ratios. The poor prognosis rate of DMVOs-MT group was insignificantly different from that of M1-MT group but lower than that of DMVOs-IVT group. Adverse events and mortality incidences were comparable among the three groups. Diabetes, first-pass recanalization, and pre-treatment NIHSS scores were independent risk factors for poor prognosis in DMVO patients after MT. MT is as effective and safe in patients with DMVOs as in patients with M1 occlusions. In patients with DMVOs, MT has higher efficacy and safety than IVT.

Precision Structuring of Free-Text Surgical Record for Enhanced Stroke Management: A Comparative Evaluation of Large Language Models.

Mechanical thrombectomy (MTB) is a critical procedure for acute ischemic stroke (AIS) patients. However, the free-text format of MTB surgical records limits the formulation of effective postoperative patient management and rehabilitation plans. This study compares the efficacy of large language models (LLMs) in structuring data from these free-text MTB surgical record. This retrospective study collected a total of 382 MTB surgical records from a tertiary hospital. An initial analysis of 30 surgical record from these records provided a guiding prompt for LLMs, focusing on basic and advanced characteristics, such as occlusion locations, thrombectomy maneuvers, reperfusion status, and intraoperative complications. Six LLMs-ChatGPT, GPT-4, GeminiPro, ChatGLM4, Spark3, and QwenMax-were assessed against data extracted by neuroradiologists and a junior physician for comparison. The all 382 surgical records were used to test the performance of LLMs. The performance of the LLMs was quantified using Accuracy, Sensitivity, Specificity, AUC, and MSE as an additional metric for advanced characteristics. All LLMs showed high performance in characteristic extraction, achieving an average accuracy of 95.09 ± 4.98% across 48 items, and 78.05 ± 4.2% overall. GLM4 and GPT-4 were most accurate in advanced characteristics extraction, with accuracies of 84.03% and 82.20%, respectively. The processing time for LLMs averaged 73.10 ± 10.86seconds of six models, significantly faster than the 427.88seconds for manual extraction by physicians. LLMs, particularly GLM4 and GPT-4, efficiently and accurately structured both general and advanced characteristics from MTB surgical record, outperforming manual extraction methods and demonstrating potential for enhancing clinical data management in AIS treatment.

Abstract 418: Targeted tirofiban use for endovascular treatment of ischemic stroke

Purpose For complex thrombus events of intracranial atherosclerotic occlusion, tirofiban, a glycoprotein IIb/IIIa antagonist, could increase the success of endovascular treatment (EVT). This study investigated the applicability of this targeted tirofiban use. Methods Stroke patients undergoing EVT were enrolled with the approval of the prospective use of tirofiban in ongoing thrombosis, re‐occlusion, and in‐stent thrombus formation. The presumptive mechanism of cerebral occlusions was divided into atherosclerotic and other etiologies. Then, the efficacy and safety outcomes of target tirofiban use were evaluated according to the location and mechanism of occlusion. Results Among those with symptomatic intracranial occlusion, 41.8% had atherosclerotic occlusion (ICAO), while 56.2% had atherosclerotic occlusions in the case of extracranial vessels. Tirofiban use rates were 24.5% of ICAO and 20.6% of extracranial atherosclerotic occlusions, while 6.8% of non‐atherosclerotic occlusions. In ICAO, tirofiban use presented a similar successful recanalization rate compared to those who did not use tirofiban (88.9% versus 86.1%), also in symptomatic intracerebral hemorrhage (2.4% versus 1.9%, P=0.81) and stroke recurrence (22.2% versus 13.3%, P=0.11). Multivariate analyses showed that ICAO, with the reference of non‐atherosclerotic occlusion, had no different effect on the successful recanalization (adjusted odds ratio, 0.70; 95% confidence interval, 0.40 ‐ 1.23), stroke recurrence (0.97; 0.55 ‐ 1.65), and SHT (0.51; 0.15 ‐ 1.36) when tirofiban use was taken into consideration. Conclusion Targeted tirofiban use may enhance the chance of recanalization in atherosclerotic occlusion without increasing the risk of safety concerns.

Abstract 367: Physiologic steal in white matter structures of non‐flow limited cerebral hemispheres as evidenced by observations of acetazolamide challenge arterial spin labeling MR

Background Acetazolamide administration can allow for comparisons between cerebral blood flow (CBF) at baseline and after acetazolamide challenge to evaluate the cerebral vasculature. While effects of augmentation have been studied in vaso‐occlusive hemispheres, little has been reported on physiologic, non‐flow limited hemispheres. Methods Patients who underwent acetazolamide challenge MRI from 2014‐2021 and a cerebral angiogram within one year were included. Patients with bilateral disease or non‐diagnostic imaging artifacts were excluded. MRIs were obtained after 1 g of acetazolamide administered 5 and 10 minutes prior to acquisition. Augmentation and steal maps were generated by comparing pre and post acetazolamide CBF images. Regression analysis, Pearson correlation coefficient, two sample t‐Test, Spearman and Mann Whitney U analyses were utilized for statistical evaluation. Results 38 Patients with unilateral cerebral vaso‐occlusive disease underwent the acetazolamide challenge. Steal and T2 hyperintensities were assessed in non‐flow limited hemispheres (NFLH) and flow limited hemispheres (FLH). A moderate correlation was demonstrated between NFLH steal and NFLH T2 hyperintensities (rs=0.48, p=0.0020). A weak correlation without statistical significance was demonstrated between ipsilateral T2 and contralateral T2 hyperintensities (rs= .27, p=.10). No correlation was found between steal severity or T2 hyperintensity and occlusion locations of stenosis. Conclusion Vascular steal phenomenon was demonstrated in the distal cerebral vasculature of cerebral white matter even in the absence of upstream flow limiting stenosis, suggesting an inherit vulnerability of these structures to hemodynamic fluctuations and possible contributing etiology to leukoaraiosis.

Abstract 372: Precision Reperfusion in Acute Ischemic Stroke: Angiography and Reperfusion after Successful Thrombectomy

Introduction Angiographically occult microcirculatory “no‐reflow” has been hypothesized to play a role in suboptimal outcomes after endovascular thrombectomy (EVT) for acute ischemic stroke. In the present study, we sought to evaluate the presence of perfusion asymmetry within infarctions present on MRI imaging following TICI 3 recanalization. Methods Consecutive patients treated between 8/2020 ‐ 7/2023 with EVT at a single institution for complete occlusions of the anterior circulation with core lab‐confirmed TICI 3 recanalization who subsequently underwent MR‐based perfusion imaging within 96 hours of EVT were evaluated for qualitative perfusion asymmetry on Tmax, CBV, and CBF, or TTP if images were not processed through RAPID. Strict exclusion criteria were employed, including ≥70% ipsilateral ICA stenosis, chronic contralateral intracranial occlusions, angioplasty/stenting during EVT or patients with prior intracranial stents, dissection, ICH (≥HI‐2, more than trace SAH), re‐occlusion during the hospitalization, or poor quality perfusion scans. Results Nineteen patients met inclusion criteria with MR‐based perfusion imaging after EVT. Occlusion locations included the cervical ICA (2), intracranial ICA (2), M1 (8), M2 (6), and M3 (1). Median NIHSS was 10. Six patients had pre‐morbid mRS≥3. MRIs were obtained at two time points: Early, median of 4.7 hours (1.5 ‐ 15.4), and Late, median of 30.0 hours (20.4 ‐ 74.4). Three of 19 patients demonstrated no infarct on any MRI in the affected territory. Of 16 patients with evidence of ischemia on MRI, 6 had punctate foci of ischemia <1.5cm within which perfusion could not be accurately assessed. Of the remaining 10 with clearly demarcated territories of stroke, 7 had evidence of at least mild hyperperfusion within the infarct bed on Tmax, CBV, and CBF. Two patients did not show any clear perfusion asymmetries within the area of infarct. No patients demonstrated sustained hypoperfusion within the infarct bed. However, one patient had initial Tmax hypoperfusion on Early MRI prior to infarct development (at 4.8hrs) followed by hyperpefusion on the Late scan (57.7 hrs) when infarct developed. Otherwise, perfusion remained consistent in all other cases between Early and Late scans. In terms of outcomes, 14/20 (70%) patients had discharge mRS 0‐2 or equivalent to baseline if pre‐morbid mRS ≥3. Of the 6 with outcomes mRS >2, three had pre‐morbid mRS≥3. Of those with no pre‐morbid disability, one improved to mRS ≤2 at 90 days. No clear association noted between poor outcome and perfusion pattern on MRI, however the single patient in whom hypoperfusion was noted on initial MRI subsequently had poor outcome (mRS 4). Conclusions In our retrospective series of highly selected patients with core‐lab confirmed TICI 3 recanalization, variable patterns of abnormal perfusion were evident on post‐EVT imaging. Hypoperfusion within ischemic tissue suggestive of microvascular no‐reflow was not frequently observed. On the contrary, most patients demonstrated hyperperfusion patterns. However, normal perfusion was also noted in a minority of cases. The precise reperfusion pattern seen after TICI 3 recanalization is likely variable and may depend on an interplay of other factors, such as imaging timing or pattern of stroke, which should be explored more in the future.

Abstract 390: Real‐world evaluation of endovascular stroke treatment using stent retrievers with drop zone technology ‐ insights from a single center study

Background The NeVa stent retriever with drop zone technology for treating acute ischemic stroke (AIS) due to large vessel occlusions (LVOs) has demonstrated safety and effectiveness in a previously completed prospective, multicenter, quality controlled, Food and Drug Administration (FDA)‐regulated clinical study (CLEAR) in highly selected sites and patients. Objective To evaluate the safety and effectiveness of revascularizing acute LVOs using the NeVa or NeVa NET devices in a real‐world setting. Methods This retrospective, single‐center, single‐arm study aimed to assess the safety and performance of the NeVa device in revascularizing LVOs in the anterior circulation within 24 hours of stroke onset. Occlusion locations included the internal carotid artery (ICA) and the M1/M2 branches of the middle cerebral artery (MCA). The primary endpoint was rate of expanded Treatment in Cerebral Ischemia (eTICI) score of 2b‐3 within 3 NeVa passes. Other key endpoints included first pass success (eTICI 2c‐3) and final reperfusion success (eTICI 2b‐3). Safety endpoint was 24‐hour symptomatic intracranial hemorrhage (sICH). Results Between December 2021 and June 2024, 96 patients were treated using a NeVa stent retriever. The occlusion sites included the distal ICA (n=5), carotid‐T (n=20), MCA‐M1 (n=53), and MCA‐M2 (n=18). Successful reperfusion (eTICI 2b‐3) within 3 passes was achieved in 85.4% (82/96) of cases. First pass success of eTICI 2b‐3 was achieved in 49.0% (47/96) of patients, with eTICI 2b67‐3 in 47.9% (46/96), and eTICI 2c‐3 in 43.8% (42/96). The final reperfusion rate (eTICI 2b‐3), including bail‐out strategies or other devices, was 91.6% (88/96); final eTICI 2b67‐3 rate was 83.3% (80/96), and final eTICI 2c‐3 rate was 75.0% (72/96). The median number of passes was 1 (IQR 1‐2). The rate of sICH was 5.2% (5/96). Three month clinical outcomes will be available at the time of the annual meeting. Conclusions The NeVa devices displayed high effectiveness in achieving revascularization. The results were comparable to previous studies, although patient variability and procedural differences may affect results and potentially outcomes.

Abstract 053: The Red 43 Intermediate Catheter For Aspiration Thrombectomy Of Distal Medium Vessel Occlusions (DMVOs): A Multicenter Experience.

Introduction Recent clinical research has increasingly supported the effectiveness and safety of mechanical thrombectomy (MT) for treating occlusions in distal medium‐sized vessels. This underscores the necessity for specialized MT devices capable of navigating the tortuous anatomy of distal cerebrovascular vessels. The recently introduced RED 43 aspiration catheter can be used as a primary catheter for distal aspiration in acute ischemic stroke. In this multicenter study, we share our collective experience using the RED 43 catheter as the primary aspiration device for thrombectomy of DMVOs. Methods We identified consecutive patients with DMVOs who underwent primary aspiration thrombectomy using the RED 43 catheter from four high‐volume comprehensive stroke centers. We collected baseline clinical data, angiographic and clinical outcomes, as well as procedural complications. Cases with large vessel occlusion that were treated according to the standard of care and subsequently developed a DMVO were labeled as secondary DMVOs. The primary outcomes were the rate of first pass effect (FPE), defined as a modified Thrombolysis in Cerebral Infarction (mTICI) score of 2c or 3 on the first pass, and the rates of successful recanalization, defined as mTICI ≥2b at the end of the procedure. We also obtained rates of good functional outcomes, symptomatic intracerebral hemorrhage (ICH), asymptomatic ICH, subarachnoid hemorrhage (SAH), and in‐hospital mortality. Results We identified 102 consecutive cases of DMVOs undergoing primary aspiration thrombectomy using the RED 43 catheter. The mean age was 70 (SD: 14) years. The medianNIHSS score was 9 (IQR 6‐14), and the median ASPECTS was 9 (IQR 8‐10). Among these, 79 cases were primary DMVOs, and 23 were secondary DMVOs. The primary occlusion locations where the RED 43 catheter was used were as follows: distal M2 MCA segment in 41 cases (40.2%), M3 MCA segment in 29 cases (28.4%), M4 MCA segment in 5 cases (4.9%), A1 ACA in 4 cases (3.9%), A2/A3 ACA in 12 cases (11.8%), and P1 PCA in 8 cases (7.8%). The rate of first pass effect (FPE) (mTICI 2c or 3 on the first pass) using the RED 43 aspiration catheter was 57% (45/79) for primary DMVOs and 61% (14/23) for secondary DMVOs. The rate of successful recanalization (mTICI ≥2b at the end of the procedure) was 83% (66/79) for primary DMVOs and 87% (20/23) for secondary DMVOs. A good functional outcome (mRS 0‐2 at 3 months) was observed in 57% of patients. One patient experienced symptomatic ICH, and two patients died during hospitalization. Asymptomatic ICH and asymptomatic SAH were observed in 5 patients (4.9%) and 7 patients (6.9%), respectively. Conclusion Our study demonstrates the safety and efficacy of the RED 43 catheter for aspiration thrombectomy of both primary and secondary DMVOs, with good rates of FPE and successful recanalization, and an excellent safety profile.

Predictors of distal embolization during thrombectomy for anterior circulation large vessel bifurcation occlusion stroke.

Distal embolization is a frequent complication of mechanical thrombectomy (MT) for acute ischemic stroke, often leading to poor clinical outcomes. The vascular bifurcations represent a specialized anatomical location, thereby augmenting the complexity of MT. The specific factors contributing to distal embolization in this context have not been thoroughly explored. This study seeks to identify the factors associated with distal embolization during MT in patients with anterior circulation large vessel bifurcation occlusion stroke. A retrospective analysis was conducted on patients who underwent MT for acute anterior circulation bifurcation occlusion stroke between January 2015 and December 2023. Baseline characteristics, procedural details, and clinical outcomes were assessed. Univariate and multivariable analyses were performed to identify predictors of distal embolization during MT. The study included 119 patients. Univariate analysis revealed significant associations between distal embolization and occlusion location, internal carotid artery (ICA) tortuosity, first-line thrombectomy strategy, and the number of device passes. Multivariate analysis identified ICA bifurcation occlusions (odds ratio (OR) 3.21, 95% confidence interval (CI) 1.188 to 8.672, P=0.021), stent retriever thrombectomy (SRT) (OR 6.177, 95% CI 1.77 to 21.555, P=0.004), and a higher number of device passes (OR 1.778, 95% CI 1.132 to 2.792, P=0.013) as independent predictors of distal embolization. ICA bifurcation occlusion, the use of SRT, and an increased number of device passes are significant predictors of distal embolization during MT in patients with anterior circulation large vessel bifurcation occlusion strokes.

Intracerebral hemorrhage risk after adjunct intraarterial thrombolysis in thrombectomy-treated acute ischemic stroke.

Intraarterial thrombolysis as an adjunct to mechanical thrombectomy is increasingly being considered to enhance reperfusion in acute ischemic stroke patients. Intraarterial thrombolysis may increase the risk of post-thrombectomy intracerebral hemorrhage (ICH) in certain patient subgroups. We analyzed acute ischemic stroke patients treated with mechanical thrombectomy in a multicenter registry. The occurrence of any (asymptomatic and symptomatic) post-thrombectomy ICH was ascertained using standard definition requiring serial neurological examinations and computed tomographic scans acquired within 48hours of the thrombectomy. We determined the risk of ICH in subgroups defined by clinical characteristics and the use of intravenous (IV) thrombolysis. A total of 146 (7.5%) patients received intraarterial thrombolysis among 1953 acute ischemic stroke patients who underwent mechanical thrombectomy. The proportion of patients who developed any ICH was 26 (17.8%) and 510 (28.2%) among patients who were and were not treated with intraarterial thrombolysis, respectively (p=.006). The proportion of patients who developed symptomatic ICH was 4 (2.7%) and 30 (1.7%) among patients who were and were not treated with intraarterial thrombolysis, respectively (p=.34). Among patients who received IV thrombolysis (n=1042), the proportion of patients who developed any ICH was 9 (16.7%) and 294 (30.7%) among patients who were and were not treated with intraarterial thrombolysis, respectively (p=.028). The risk was not different in strata defined by age, gender, location of occlusion, preprocedure National Institutes of Health Stroke Scale score, time interval between symptom onset and thrombectomy, Alberta Stroke Program Early CT Score, systolic blood pressure, and serum glucose concentrations. In patients undergoing mechanical thrombectomy, the risk of any ICH and symptomatic ICH was not increased with intraarterial thrombolysis, including in those who had already received IV thrombolytics.

PSPMoni: A Robust Wear Monitoring Method of Pantograph Slide Plate

The pantograph slide plate (PSP) plays a crucial role in the daily maintenance of trains by transmitting electrical energy from the contact wire (CW) to the train. Automatic monitoring of PSP wear condition is essential to notice abnormal wear promptly. In field applications, the target PSP edge may be obscured by the rear side PSP due to the operating attitude of the pantograph, leading to false detections and interfering with the field maintenance work. Meanwhile, the scenario of the PSP occlusion is characterized by randomness, which brings a considerable challenge to the reconstruction of the occluded edges. A robust PSP wear monitoring method is proposed to improve the performance of wear detection in field applications, considering the PSP occlusion scenarios. Firstly, the wear area of the PSP is localized using the YOLOv5s model. Subsequently, a fusion of the morphology method and the Canny operator is employed to extract the edge of the PSP. Different occlusion types are identified through detailed observation, and corresponding edge reconstruction methods are proposed for occluded edges. Finally, a robust wear condition evaluation method and five evaluation criteria for assessing wear condition are introduced. Experimental results demonstrate that the system achieves accurate PSP wear detection with an accuracy of 0.6 mm, and the reconstructed edge at occlusion locations closely matches the target edge compared to other automatic systems.

The impact of general anesthesia versus non-general anesthesia on thrombectomy outcomes by occlusion location: insights from the ETIS registry.

Identifying the optimal anesthetic technique for mechanical thrombectomy (MT) remains an unresolved issue. Prior research has not considered the influence of occlusion site when comparing general anesthesia (GA) with non-GA. This study evaluates the differential impacts of the anesthetic technique (GA vs non-GA) on outcomes according to the location of occlusion. This is a retrospective analysis of the ETIS (Endovascular Treatment in Ischemic Stroke) registry. Patients with anterior circulation large-vessel occlusion treated with MT were included. Patients were divided into groups according to the location of occlusion. Inverse propensity score weighting analysis was used. Among 2783 patients included in the propensity score analysis, 669 (24%) received GA. In the total cohort, GA was not associated with favorable outcome, excellent outcome, successful reperfusion, or complete reperfusion. GA was associated with higher odds of parenchymal hemorrhage (OR 1.42, 95% 1.05-1.92) but not symptomatic intracranial hemorrhage. GA was associated with Alberta Stroke Program Early CT Score progression (OR 1.36, 95% CI 1.11-1.68). In the internal carotid artery occlusion group, GA was associated with higher odds of mortality (OR 1.94, 95% CI 1.15-3.27). In the M1 group, GA was associated with lower odds of complications (OR 0.41, 95% CI 0.19-0.92). In the M2 group, GA was associated with successful reperfusion (OR 2.79, 95% CI 1.02-7.64). In addition, the complication rate was lower with GA (2.7% vs 7%), although the association was not significant in adjusted analysis. While GA and non-GA techniques did not differ significantly in functional outcomes, the influence of GA on angiographic and procedural safety outcomes was location dependent, underscoring the importance of a tailored anesthesia technique in MT procedures.

Relationship between carotid web morphology on CT angiography and stroke: A pooled multicenter analysis.

The Carotid web (CaW) is a cause of stroke, particularly in younger individuals. However, the frequency and the radiological features of the web's morphology associated with stroke risk are uncertain. We determined the CaW radiological features on computed tomography (CT) angiography associated with ipsilateral stroke. Data from six studies of patients with acute ischemic stroke were pooled. Identification and measurement of CaWs were performed by experienced readers using baseline neck CT angiography. We assessed six 2D CaW radiological features on sagittal oblique images, namely, main axis length, thickness, height, base width, distance to wall, and angle between the web main axis and carotid wall, and CaW volume on 3D images. CaWs were divided into symptomatic if acute ischemic stroke was in the ipsilateral internal carotid artery territory and its etiology was undetermined and asymptomatic if one condition was unmet. Univariable and multivariable analyses were conducted to assess the association between each radiological CaW feature and symptomatic CaW. Of the 3442 patients in the pooled data with assessable CTAs, 60 (1.7%) had CaW. In patients with CaW, median age was 59 (interquartile range [IQR]: 50-68) years, 60% were women, and 3 patients had bilateral CaWs. There were 39 (62%) symptomatic and 24 (38%) asymptomatic CaWs. Patients with symptomatic CaW were younger (55 (IQR: 49-61) years versus 69 (IQR: 52-75) years), had lower rates of hypertension (9 (25.0%) versus 12 (57.1%)) and more intracranial large vessel occlusions compared to patients with asymptomatic CaWs. After adjusting for age, hypertension, and occlusion location, CaW length (adjusted odds ratio (aOR) 1.84 (95% confidence interval [CI]: 1.03-3.28)), thickness (aOR: 2.31 (95% CI 1.08-4.97)), volume (aOR: 1.07 per 1 mm3 increment (95% CI: 1.01-1.12)), and angle relative to the carotid wall (aOR: 0.95 (95% CI: 0.91-0.99)) were associated with symptomatic CaW. Radiological assessment of CaW morphology may determine its potential causal role in ischemic stroke etiology. Symptomatic CaWs tend to be longer, larger, and oriented at more acute angles relative to the carotid wall as compared to asymptomatic CaWs.

AC-ASPECTS, ACh-ASPECTS, and H-ASPECTS: new imaging scales to assess territorial and total cerebral hemispheric ischemic injury.

The extent of ischemic injury in acute stroke is assessed in clinical practice using the Acute Stroke Prognosis Early CT Score (ASPECTS) rating system. However, current ASPECTS semi-quantitative topographic scales assess only the middle cerebral artery (MCA) (original ASPECTS) and posterior cerebral (PC-ASPECTS) territories. For treatment decision-making in patients with anterior cerebral artery (ACA) occlusions and internal carotid artery (ICA) occlusions with large ischemic cores, measures of all hemispheric regions are desirable. In this cohort study, anatomic rating systems were developed for the anterior cerebral (AC-ASPECTS, 3 points) and anterior choroidal artery (ACh-ASPECTS, 1 point) territories. In addition, a total supratentorial hemisphere (H-ASPECTS, 16 points) score was calculated as the sum of the MCA ASPECTS (10 regions), supratentorial PC-ASPECTS (2 regions), AC-ASPECTS (3 regions), and ACh-ASPECTS (1 region). Three raters applied these scales to initial and 24 h CT and MR images in consecutive patients with ischemic stroke (IS) due to ICA, M1-MCA, and ACA occlusions. Imaging ratings were obtained for 96 scans in 50 consecutive patients with age 74.8 (±14.0), 60% female, NIHSS 15.5 (9.25-20), and occlusion locations ICA 34%; M1-MCA 58%; and ACA 8%. Treatments included endovascular thrombectomy +/- thrombolysis in 72%, thrombolysis alone in 8%, and hemicraniectomy in 4%. Among experienced clinicians, inter-rater reliability for AC-, ACh-, and H-ASPECTS scores was substantial (kappa values 0.61-0.80). AC-ASPECTS abnormality was present in 14% of patients, and ACh-ASPECTS abnormality in 2%. Among patients with ACA and ICA occlusions, H-ASPECTS scores compared with original ASPECTS scores were more strongly associated with disability level at discharge, ambulatory status at discharge, discharge destination, and combined inpatient mortality and hospice discharge. AC-ASPECTS, ACh-ASPECTS, and H-ASPECTS expand the scope of acute IS imaging scores and increase correlation with functional outcomes. This additional information may enhance prognostication and decision-making, including endovascular thrombectomy and hemicraniectomy.

Safety of acute internal carotid artery stenting during endovascular thrombectomy in patients with acute ischemic stroke: a retrospective analysis of the OPTIMISE registry

BackgroundThe optimal management of tandem carotid lesions during endovascular thrombectomy (EVT) remains uncertain. The safety and efficacy of acute carotid artery stenting (aCAS) are debated, including safety concerns such as...

Endovascular thrombectomy versus medical management on outcomes with infarct volumes more than 70 mL.

Endovascular thrombectomy (EVT) in patients with large infarct volume remains controversial. The aim of this study is to compare clinical outcomes between EVT and medical management in acute large vessel occlusion with infarct volumes larger than 70 mL on diffusion-weighted magnetic resonance imaging (DWI). A prospective observational cohort study was conducted, including patients with anterior cerebral circulation occlusion due to ischemic stroke with infarct volumes larger than 70 mL within 24 h of onset between July 2018 and June 2023. Eligible patients were divided into two groups: the EVT group and the medical management (non-EVT) group. The main outcomes were functional independence and mortality at 90 days. To assess clinical endpoints, we selected variables including age, NIHSS score, infarct volume, and occlusion location for 1:1 propensity score (PS) matching and PS adjustment using inverse probability of treatment weighting (IPTW). Among the 131 identified patients (mean [SD] age, 69.9 [13.7] years; 58 female), the median infarct volume was 123.6 mL. Of these patients, 75 (57.3%) underwent EVT. After PS adjustment, EVT was not associated with functional independence (10.9% vs. 10.9%; p = 1.000) or mortality (43.5% vs. 47.8%; p = 0.675). Additionally, after PS adjustment using IPTW, EVT was also not associated with a functional independence (15.8% vs. 13.7%; p = 0.767) or mortality (46.8% vs. 44.0%; p = 0.762). This study provides real-world evidence regarding infarct volumes larger than 70 mL, indicating that EVT does not provide benefits compared to medical management alone when considering age, NIHSS score, infarct volume, and occlusion location.